‰ NOW 25 WPM ‰ TEXT IS FROM SEPTEMBER 2007 QST PAGES 68 AND 100 ‰
WITH HF RADIOS. MANUFACTURER HENDRICKS QRP KITS, 862 FRANK AVE, DOS PALOS,
CA 93620 TEL 209 704 3522 WWW. QRPKITS. COM. RICH ARLAND, W3OSS, IS THE
AUTHOR OF LOW POWER COMMUNICATIONS, PUBLISHED BY ARRL. THE REVISED THIRD
EDITION WILL BE AVAILABLE SHORTLY AFTER YOU READ THIS REVIEW. CHECK THE
ARRL WEB SITE FOR MORE INFORMATION. GAMMA RESEARCH HPS 1A SWITCHING POWER
SUPPLY REVIEWED BY MICHAEL TRACY, KC1SX ARRL LAB TEST ENGINEER LIGHTWEIGHT
13R8 V DC SWITCHING POWER SUPPLIES ARE INCREASINGLY POPULAR FOR
COMMUNICATIONS USE, LARGELY THE RESULT OF QUIET AT RADIO FREQUENCIES
DESIGNS. SWITCHING POWER SUPPLIES IN CONSUMER ELECTRONICS EQUIPMENT OFTEN
USE SWITCHING SIGNALS IN THE 25 TO 35 KHZ RANGE AND MINIMAL FILTERING,
RESULTING IN SPURS OF THE SAME FREQUENCY SPACING ACROSS THE HF RANGE. THE
SPURS TEND TO MOVE UP AND DOWN THE BAND, PRESENTING A REAL HEADACHE TO
‰ FROM PAGE 100 ‰
N9ER/341 N9MR/339 NA7AA/337 NA8D/334 NE0DX/331 NM0F/336 NO3N/340 NQ7R/339
‰ END OF 25 WPM TEXT ‰ QST DE W1AW ƒ